The proposed project is aimed at examining two major aspects of the regulatory biochemical functions of glucocorticoids in specific catecholaminergic and serotonergic neurons in the brain. One aspect is concerned with the role of these hormones in biochemical regulation of neurotransmission, particularly the two rate-limiting neurotransmitter-synthesizing enzymes, tyrosine hydroxylase and tryptophan hydroxylase. The other aspect is concerned with the biochemical characterization of cytosol glucocorticoid receptor protein(s) in specific types of neurons, and the regulatory effect of glucocorticoids on the adenylate cyclase system. Work in progress has revealed that corticosterone can prevent the inactivation of brain tyrosine hydroxylase and tryptophan hydroxylase by cycloheximide, and that the corticoid may be involved in the phosphorylation process of tryptophan hydroxylase. These mechanisms as well as the receptor protein are currently under investigation.